JPH0218319A - Novel zeolite of ton structure, and its production and use - Google Patents

Abstract

PURPOSE: To provide novel zeolite showing specific X-ray diffraction, containing fluorine and having a TON-structure, providing an improved acidic characteristic and useful for adsorbing and catalytic action.

CONSTITUTION: TON-structure type zeolite is synthesized by the following processed (a)-(c): (a) a reaction mixture containing water, at least one silica source, at least one aluminum salt source, at least one activating agent source containing a fluoride F^- ion and at least one structuring agent source capable of supplying an organic cation and having ≤pH 9 is prepared, and in this case, the composition (molar ratio) of the mixture is that, SiO₂/Al₂O₃ is ≤20, F^-/SiO₂ is 0.1-6 (organic cation)/SiO₂ is 0.1-6 and H₂O/SiO₂ is 6-200; (b) the mixture is kept at 250°C at most by heating unit a crystalline compound is obtained; and (c) The compound is fired mat ≥350°C. The zeolite obtained by the method contains 0.005-2 wt.% fluorine and has a molar atomic ratio SiO₂/Al₂O₃ of 50-4,000 and a specific X-ray diffraction pattern.

COPYRIGHT: (C)1990,JPO

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a new zeolite of the TON structure type and a method for producing this zeolite.

[Prior art and its problems] Zeolites are crystallized tectosilicates.

Their three-dimensional structure is composed of a set of tetrahedra TO4 that share their vertices. Two different tetrahedra share only one oxygen. In the most common aluminosilicate type zeolites, T represents tetravalent silicon as well as trivalent aluminum. The molecular-sized cavities and pores of the aluminosilicate backbone accommodate cations that compensate for the charge deficiency associated with the presence of trivalent aluminum within the tetrahedron.

The chemical composition of zeolites containing A/ and St elements in their framework can be approximately represented by the following formula: M2/, OA/ OxsLO2 1'23', where M is the valence n cation, such as an alkali, supra-alkali or organic cation; X varies from 2 to infinity according to the structure.

In this case the zeolite is microporous silica. ) Each type of zeolite has a different porous structure. Changes in size and shape from one type to another give rise to different adsorption and catalytic properties.

Only molecules of a certain size and shape can enter the pores of a special zeolite. The chemical composition, especially in the nature of ion-exchangeable compensating cations, is also an important factor mediating the selectivity of adsorption of these substances, especially the catalytic properties.

Due to their geometrical selectivity and cation exchange properties, zeolites are useful both in catalysis (catalytic clubking, hydrogenation clubking, isomerization, etc.) as well as in adsorption (gas drying, separation of aromatic compounds, etc.). , used on a large scale industrially.

Although many zeolites of the aluminosilicate type exist in nature, the search for materials with new properties has recently given rise to a wide variety of methods for the synthesis of these aluminosilicates with a zeolite structure. Among the new structures that have recently been successfully synthesized, there are zeolites of the TON structure, which are also referred to by researchers as: THETA-1 European Patent (E, P, 57049) 18
+-1 European Patent (E, P, 87017) ZSM-22 US Patent (U, S, P, 4481177) NU-10 European Patent (E, P, 77824) KZ-2 (Publication: Zeolite 3 (19f13) )8).

All these zeolites corresponding to the same structural type were obtained in a synthetic medium, called conventional medium, that is generally an alkaline medium with a pH of 9 or higher.

In contrast to syntheses carried out in fluoride media, syntheses carried out in conventional alkaline media (OH-) have several disadvantages.

In fact, in basic media, most of the synthetic zeolites are metastable, and during the synthesis there is a risk of the appearance of a more stable solid phase and also the risk of undesired phase precipitation.

This difficulty only increases when manufacturing volumes increase, ie when moving from laboratory testing to the industrial stage. Moreover, in basic reaction media these metastable zeolites can only be obtained by strong supersaturation of the active species in the medium. This results in rapid nucleation resulting in small sized zeolite crystals, the average size of these crystals being in the micrometer range. Therefore, it is difficult to produce crystals of the largest size. By the way, in some applications of ion exchange, adsorption or catalysis, it would be advantageous to operate with crystals of large size. This would for example avoid conditioning the zeolite by agglomeration, with all the disadvantages this entails.

Many applications, especially in acid catalysis, require zeolites in protonic form, completely free of their alkali or alkaline earth compensating cations introduced during synthesis. A repeated, time-consuming ion exchange process with cations NH+, then exchange them with cations H+
It can be obtained by a calcination method that decomposes it into . This ion exchange step may be omitted if the alkali or alkaline earth cations can be completely replaced by the cations NH+ during the synthesis. Or this is the pH
is not possible when substantially exceeds 10. NH+ is converted to NH3 under these conditions. Additionally, syntheses carried out in pl() where the cation NH+ is stable are difficult and time consuming due to the low solubility of the silica source at these low pHs.

Another advantage of the synthesis carried out in a fluoride medium over conventional synthesis is that it yields solids with different acidic and ion exchange properties. Acidic catalysts prepared from solids obtained in fluoride media have improved catalytic properties. It is very important at this stage to note that the crystal structure of the solid is not sufficient to completely define the properties of this solid, more specifically its acidic properties, which play a crucial role in catalysis. be.

Contrary to their homologues synthesized according to the prior art, the zeolites of TON structure produced according to the invention contain fluorine after the synthesis step and also after the removal step of the organic compounds introduced during the synthesis. . As you will see later,
Fluorine gives the TON structure zeolite according to the invention quite special acidic properties and ion exchange properties.

The present invention is therefore directed to a new synthetic zeolite of the TON type, a new method for the synthesis of this structure, which avoids the above-mentioned disadvantages and gives the zeolite according to the invention properties, in particular improved acidic properties.

The zeolites according to the invention may be used in particular in adsorption and catalysis.

[Means for solving the problem] The zeolite according to the present invention usually has the following general formula: % formula % (wherein M is a proton or a metal cation, and n is the valence of M) Production of the zeolite according to the present invention In the process, said proton or metal cation is at least one cation, such as NH+ or n-butylammonium, dipentylammonium, 1,4-diammonium, pentane, n −
The heat of pentylammonium and/or cations of non-decomposable metals which have (or have not) left the reaction medium, such as alkali and/or alkaline earth cations, or other metal cations specified below. Resulting from decomposition.

The zeolite according to the invention is characterized by: (a) x being a number from 50 to 40000, where x is 5i0
2/A/203 molar ratio); (b) X-ray diffraction chart shown in Table I of the specification; (C) (measured, for example, after the organic compound removal step below) 0.005 to 2
Fluorine content in weight%.

The new zeolites of TON structure according to the invention generally have a crystal size of 0.1 to 250 μm (micrometer), i.e. 0.1 to 250 μm. I x 10-6m ~250 x 10-
6 m1 preferably 2-130 um (2X 10-
6m-130X10-6m).

- in the shell, the process for producing a crystalline synthetic zeolite according to the invention is characterized in that: (a) at least one source of water, at least one source of silica, at least one source of aluminum salts, at least one source containing fluoride ions; two mobilizing agents (agen)
at least one structuring agent capable of supplying organic cations;
forming a reaction mixture with a pH below 9 consisting of a source (SiO/A/203 ≧20F −/S), said mixture having a composition in a molar ratio within the following values:
,t O20,1m6 Organic cation/5IO20,1~6 H20/S 102 6~200(b)
maintaining the mixture at a heating temperature of at most about 250°C until a crystalline compound is obtained; and (e) calcining the compound at a temperature of 350°C or higher.

After the removal step of organic compounds (conditions specified below), the presence of fluorine in the zeolite of TON structure according to the invention, preferably in a content of 0.02 to 1.0% by weight, has an acidic character and a solid causes a change in the ion exchange properties of In this case, these are the TONs known in the prior art.
Its structure is completely different from that of zeolite. The solid according to the invention is characterized by an infrared vibrational spectrum in the range 3800-3500 cm-'. This is the ratio S i /A /
Compared to the nearby zeolite with a conventional TON structure,
The structural group S i -OH (3730-3750 Rho 1 band) and the structural group A / -OH (8580-3640 cm-') have almost no strength and are even insignificant.
Band) represents the band conventionally assigned.

The absence or almost absence of structural groups A10H in the zeolites according to the invention is confirmed by the ion exchange capacity of these solids. In fact, cations such as Na”
K” Ga”pt < Na 3) 4”*
The ion exchange capacity for is much smaller than the total ion exchange capacity that can be calculated from the aluminum content of the crystal framework.

These solids, which have no or few structural hydroxyls and have a reduced ion exchange capacity, surprisingly have pronounced acidic properties. Thermal desorption of ammonia, which can thus take into account the overall acidity of the solid (number and strength of different types of acidic sites), produces a desorption spectrum that clearly shows that the solid according to the invention is highly acidic. arise. The thermal desorption spectrum of ammonia is
Comparable to that obtained using conventional TON structure zeolites. However, it is clear that the acidity of the solids according to the invention has different properties.

Without wishing to be bound by any particular theory, it is believed, for example, that a solid according to the invention has a moiety of the following type: instead of a conventional skeletal moiety.

The exact nature of the acidic sites present in the solid state of the TON structure according to the invention is not yet clear; however, these sites are largely associated with the presence of fluorine;
It is clear that these properties differ from the acidic sites of zeolites with conventional TON structure.

By special treatment it is possible to remove some or all of the fluorine contained in the solids according to the invention without changing their crystallinity.

A technique that can be used to defluorinate solids consists of carrying out a treatment in NH4OH solution (treatment under pressure), for example at temperatures between ambient temperature and 150<0>C.

Partial or complete removal of fluorine results in: On the one hand, the accepted quotas in the scientific literature (att
about 3740 to 360, corresponding to the terminal silanol group and the Al-OH structural group, respectively.
The appearance in the IR spectrum of two bands located at 8.8-1 and, on the other hand, the recovery of the ion exchange capacity as can be calculated from the aluminum content of the framework of the solid.

Therefore, depending on the defluorination treatment, Si/A with the same skeleton
/ ratio, an amount of the groups A/-OH and S 1-
Solids containing OH as well as various ion exchange capacities can be obtained. Therefore, the partially defluorinated solid contains, in addition to acidic sites of the Al-OH type that can serve as ion exchange sites, during synthesis, although their exact nature is still not completely understood. Contains special acidic sites that undeniably result from the introduction of fluorine into the solid.

More precisely, the synthetic method consists of: (a) water, at least one source of silica, optionally a source of aluminum salts, at least one source of mobilizing agent comprising fluoride ions (F-), and organic cations. , such as n-butylammonium cation (nBUTA"), dipentylammonium cation (DIPENTA") and 1
．． 4-diammonium pentane cation (DIAPE)
NT”), n-pentylammonium cation (nP
forming a reaction mixture below pHIO consisting of at least one structural agent source capable of providing ENTA''), said mixture having a composition in the following molar ratio: SiO2/Al2O3≧20F-/St O20,1-6 organic cation/SiO20,1-6H20/SiO
26-2o.

(b) at most about 250°C until a crystalline compound is obtained;
and (e) calcining the compound in an oxygen-containing medium at a temperature of at least 350°C, preferably at a temperature of at least 450°C.

Advantageously, the interior is made of polytetrafluoroethylene (PTF).
E) in an autoclave coated with about 60-210℃
, preferably 70 to 190°C, depending on the reaction temperature
for a period of time which may vary from ~1300 hours;
The reaction mixture may be heated until a crystallized solid is obtained. The solid is separated from the mother liquor by filtration, which is then washed with distilled water.

Advantageously p) 14-10. Preferably at pH 6-9,
A reaction mixture may be prepared.

According to a preferred method of preparation, the molar ratio of the components of the reaction mixture may be in the following range (expressed as molar ratio): Agent/SiO21-3 H20/SiO215-8° A supplementary salt is added to said mixture in a complementary salt/SiO2 molar ratio of generally about 0.1-4, preferably 0.2-0.5;
and/or at least one crystal nucleus of the zeolite formed according to the invention - generally from 0.01 to 0.1
, preferably about 0.02-0.03 crystals/Sio
Two weight ratios may be added such that the morphology and size of the crystals as well as the kinetics of the crystallization reaction are advantageously controlled.

Advantageously, the zeolite crystals are grown at a temperature of about 520-800°C.
The zeolite is then calcined under a dry gas atmosphere, such as air or an inert gas atmosphere, in order to decompose the structuring agent present within the pores of the zeolite.

The operation may advantageously be carried out in a stirred medium.

This allows the reaction time to be considerably shortened.

The pl+ of the reaction medium below lθ can be obtained directly from the reactant or reactants used or by the addition of acids, bases, acid salts, basic salts, or supplementary buffer mixtures.

Many sources of silica can be used. hydrogel,
Aerogels, silica in the form of colloidal suspensions, as well as precipitation of soluble silicate solutions or silicic acid esters, such as the tetraethyl ester of orthosilicic acid 5i (QCH)
or complexes such as sodium fluorosilicate Na 2 Si
F or ammonium fluorosilicate (NH4)2Si
Mention may be made of the silica resulting from the hydrolysis of F6.

Among the ammonium salts used, preferably hydrated aluminum chloride: A/C/ 6H0, nonahydrated aluminum nitrate Al(NO3)3.9H20, aluminum sulfate with 16 water molecules, or trihydrated fluorine Aluminum chloride A/F ・3H20 shall be selected. Alternatively, instead of starting from a source separated from silica and aluminum salts, a source in which the two elements are combined may be used, for example a freshly precipitated aluminosilicate gel.

The fluoride anion F- generally comprises the structuring agent or ammonium or alkali metal salts, such as NaF, N
HF, NH4HF2, nBUTAP, DIPENT
A-F, DIAPENT-F, nPENTA-
P or in the form of hydrolysable compounds capable of releasing fluoride anions in water, such as silicon fluoride S iF 4 or ammonium fluorosilicate (NH) S I F 6 or sodium fluorosilicate Na SiF 6 may be introduced.

Structuring agent cation n BIITA”, DIPE
NTA, DIAPENT'', nPENTA+ are added, preferably in the form of the corresponding amines or after their salt formation, for example with hydrofluoric acid. In order to bring the pH of the medium to the desired value, optionally for supplementation. The acids or acidic salts, bases or basic salts added to are common acids, such as HF5HC/.

HNOHSo CI C0OH, there are 3ゝ 2
4ゝ 3 or acidic salts, e.g. NHHFKHF 4 2ゝ 21 NaHSO Ordinary bases, e.g. NH4HF2 Na Co CHCOONa, Na23ゝ 2
3.3S, NaH3 or a buffer mixture, e.g. (CH3COO
HSCH3C0ONa) or (NH40H, NH4C
/) may be selected.

After the removal step of organic cations and optionally a partial or total defluorination step, at least one member of the periodic table of elements is added to the zeolite of the TON structure according to the invention by ion exchange techniques well known in the prior art. One element may be introduced. The cation of this may be prepared in an aqueous medium and corresponds to the first IA, n[A of the Periodic Table of the Elements.

It may be selected from the group consisting of IB, I[B, mB, IVB and ■A group. For example, alkali cations, alkaline earth cations, rare earth cations, Fe"Fe"C
o”Co”Ni”Cu”Zn”A
g'Pt'' and the like.

The identification of the zeolites of TON structure obtained by this method is carried out in the usual manner from their X-ray diffraction diagrams. This diffraction diagram can be obtained by a diffractometer using conventional powder methods using copper alpha lines. An internal standard allows the value of the angle 2θ associated with the diffraction peak to be accurately determined.

Various distances dhk/ between the networks that characterize the sample are calculated from the Bragg relation. According to the Bragg relation, an estimate of the measurement error delta (d) for d is calculated according to the absolute error (2θ) given to the measurement of 2θ. With the presence of an internal standard, this error is minimized, typically ±0.05@. The relative intensity 1/Io given to each position of 'hk/ is evaluated from the height of the corresponding diffraction peak. This height is the Debye-Sherrer
It may also be determined from a chamber of negative photographic film. Symbolic scales are often used to characterize this intensity: FF-very strong, F-strong, l
F-medium to strong, m-medium, f-medium to weak, f-weak, rr-very weak, rrr-extremely weak (tres trys
raible).

Table 1 shows the characteristic X-ray diffraction diagram of the TON structure zeolite obtained according to the invention before calcination. d
In the column of various reticular shapes hk/distance! The extreme values that d can take are shown. For each of these hk/ values, the measurement error (d) must be given hk/. This is typically between ±0o07 and ±0.002 depending on the value of 2θ.

EXAMPLES The following examples illustrate the invention but do not limit its scope.

Table 1 Example 1 Preparation of Zeolide T (IN) with 5iO/A/203 molar ratio greater than 34000 In this example, the organic structuring agent used was
n-pentylamine. 40% hydrofluoric acid 8.6c
m3 is used to prepare the di-n-pentylamine salt of formula (CH)NHF- by salt formation of the corresponding amine (20 cm').

8 Gam' of distilled water are added to the salt thus formed. The solution obtained is mixed with 5.84 g of finely ground silica obtained by thermal hydrolysis of silicon tetrachloride, sold under the name "AERO9IL" by DEGLISSA. It contains about 3% water by weight and the aluminum weight content is less than o,ooa%.

The molar composition of the reaction mixture is as follows; IS
i O2 (Aerosil) 11 (C5H11)
2Nu, 2HF, 46120° introduced molar fraction: 0°097° mixture (pH-5~6) was heated at 170°C for 8 days to 120 co' polytetrafluoroethylene.
Heat in an autoclave containing a flask.

3.2 g of needle-shaped crystals with an average size of (20×2) micrometers (μm) are collected.

The chemical analysis of the obtained solid, expressed in weight percentages, is as follows: Sio 2%-90,8, (CH)NH"hydrate-8,2, F-%-1%.

The X-ray diffraction diagram is quite similar to that in Table 1 of the specification.

After calcination at 850° C. for 5 hours in air, the observed weight loss is 9% and no significant structural changes are observed. At that time, the fluorine element content was 0.61% by weight.

Example 2 This example illustrates the possibility of operating with a different structuring agent source than that of Example 1 in a stirred medium and in the presence of crystal nuclei.

In the second case, the structuring agent is 1,4-diaminopentane. Otherwise, the silica and fluoride sources are the same as in Example 1.

This amine is also pre-salted with hydrofluoric acid.

The molar composition of the mixture is as follows =ISiO(
aerosil) S IC5H14N2゜2.5 HF
, 16H20°.Mor fraction introduced: 0.05° Finely ground crystals of zeolite TON, obtained by a method analogous to Example 1, are added to the reaction mixture.

The synthesis medium (pH-8) is placed in an autoclave of the same type as in the previous example. This is then brought to a temperature of 170° C. for 3 days (rotation of the autoclave around the horizontal axis) in a dryer equipped with a stirring device.

After the reaction, the final pH is 8.5. 2.7 g of zeolite TON is recovered.

The X-ray diffraction diagram of this zeolite is the same as that in Table 1.

The solid s iO2/A/203 molar ratio is 300
00 or more. The size of the crystal is 20X2 micrometers (X 10-6m).

Example 3 Preparation of zeolite TON according to the invention from structuring agents different from those used in Examples 1 and 2 This example illustrates the possibility of using n-butylamine as structuring agent.

The silica and fluoride sources are the same as in the previous example.

The molar composition of the mixture is then: 0.04S i 02 (aerosll) 5C4H9
NH2SO,04HF, 0.96H20° initial pH -8; 0.048 g of zeolite from Example 1)
Crystal nucleation with TON.

The heating conditions in the autoclave are as follows: Temperature: 170°C; Duration = 3 days; Stirring speed: 10t
, lllIn After synthesis, the pH of the reaction medium is 9 and the product (2,31
g) shows no trace of amorphous compounds.

The crystals obtained are needles with an average length on the order of several hundred micrometers.

The X-ray diffraction chart is similar to that in Table 1 of the specification. The solid SiO2/A12o3 ratio is 30,000 or more.

The zeolite calcined at 800 °C loses 8.1% by weight, its fluorine content is 0.08%, and the solid X-ray diffraction diagram shows no change compared to that of the synthetic crude product. do not have.

This zeolite placed in a humidifier under a relative water vapor pressure P/Po=0.8 remains as hydrophobic as before.

Example 4 Preparation of the zeolite TON according to the invention from a silica source different from that of the previous examples In this case, the tetraethyl ester of orthosilicic acid 5t (
A silicic acid gel is prepared by hydrolysis of QCH).

25cm' Si(OC2H5) 4 and 50cm
' water is refluxed for 3 hours.

After precipitation of the silicic acid gel, the ethanol formed during hydrolysis is removed by distillation. The gel is then dried at 80° C. for 2 hours and then finely ground.

The weight proportion of silicon is 39%.

Then make a mixture with the following molar composition: ・l5iOICHNHIHF.

2ゝ49 2ゝ24H20゜mol fraction, ■0.04゜n-butylamine is salted in advance with hydrofluoric acid. The whole is placed in an autoclave of the same type as the previous example. The operating conditions are as follows: Initial pH near-8 Reaction temperature: 170 °C Stirring speed: 10 t, min −' After 2 days of synthesis (final p) t-7-8), a lot of deposits (amas) were removed. 2.1 g of solid are obtained. Observation of these by optical microscopy reveals that they consist of a tangle of fibrils with an average size on the order of 40 micrometers.

The X-ray diffraction diagram of the synthetic crude product is the same as that in Table 1.

After removal of the organic structuring agent by calcination at 800° C., the zeolite TON placed in a humidifier under a relative water vapor pressure P/Po−0,8 remains hydrophobic.

At that time, the S i /A 1 molar ratio is 18000 or more, and the fluorine element content is about 0.08%. The crystal size is 30 x 3 micrometers (X 10-6 m
).

Example 5 S0/Ae203 ratio - Preparation of 200 noseolite TON Fluorination of n-butylamine by salt formation of the amine (8,776 g) with hydrofluoric acid (4,8 g) at 50 °C Prepare salt.

Then 9.12 cm3 of water, 0.110 g of aluminum trihydrate (Al F 3H20).

3ゝaerosil silica 2.40g, and Example 3
Silicon zeolite T produced by a similar method.

Add 0.048 g of N crystal nuclei to the whole.

The molar composition of the reaction mixture is shown below: l5iO0,02A/F 3HO.

2ゝ 3ゝ 2 3CHN, 3HF, 18H20゜Molar fraction introduced: 0.04゜Reaction medium (
Initially p) I-9) is placed in a 120 cm' autoclave. This is then dried in a dryer equipped with a stirring device.
170℃ for 5 days (rotation speed 10t, 1n-')
.

After the reaction (final p11-8-9), 2.08 g of solid is recovered. This was washed, filtered, and then dried in a dryer at 90°C.
Dry with. The crystals are acicular and their average size is around (30×3) m.

The X-ray diffraction diagram of the synthetic crude product is quite similar to that in the specification (Table 1).

After calcination at 650”C in air and after removal of the organic structuring agent, the SiO/Al2O3 molar ratio of zeolite TON is 2.
00, and its fluorine content is about 0.3% by weight.

In the example, a large amount of SiO/A/203 molar ratio -200
We illustrate the possibility of producing zeolite TON using

The operating method used is exactly the same as in Example 5.

Using 50% of the indicated molar amounts, prepare a mixture with the following molar composition: I S i O2(aerosll), 0.02A
/F 3.3HO,3CHN,3HFS16H20° The reaction is started with 0.6 g of zeolite TON prepared according to Example 5.

The mixture (pH-8) is distributed into three autoclaves of 120 (to) 3. This is then heated at a temperature of 170° C. for 5 days. Final pH is 9.

26.5 g of zeolite TON is recovered. The needle-shaped crystals have an average size of 50 micrometers.

Chemical analysis of the compound was performed using a SiO2/Al2o3 ratio of -200
, and a fluorine content of 0.6% by weight.

After calcination at 700° C. under air, the product placed in a P/Po-0,8 humidifier adsorbs 1.8% by weight of water.

The X-ray diffraction diagram is quite similar to that in Table 1.

Example 7 Zeolite TON with a SiO/Al2O3 ratio of -240 using a different fluoride source than that used in the previous example
Preparation of In this preparation, ammonium trihydrofluoride NH4HF2 is substituted for hydrofluoric acid as the fluoride agent source.
Use.

Otherwise, the silica and amine sources are the same as in Example 6.

The molar composition of the mixture thus used is: I Si O2 (aerosil), 0.02A
/ F 3, 3H0, 3CHN, 1.5 NH4HF2
．． 18H20° initial pH near ~8° crystals of aluminosilicate zeolite TON are added to the preparation.

The reaction mixture, placed in a 120 co+' stainless steel autoclave, was brought to a temperature of 170 °C for 3 days in a dryer equipped with a stirring device (v -1OL, 5ln-
').

After the reaction, the final pH is (7-8). The solid obtained is washed, filtered and then dried in an oven at 90°C.

The resulting fibers are 80-60 micrometers (30X
1G-6m to eox 10-6m). The solid state X-ray diffraction chart is exactly the same as that in Table 1 of the specification.

After 5 h of calcination at 650 °C in air, no significant structural changes are observed and chemical analysis of the zeolite yields a Si/A/ratio of −120.

The ffi content of elemental fluorine is then 0.07% by weight.

Example 8 SiO/Al2O according to the invention from structuring agents and aluminum sources different from those of Examples 5.6 and 7
Preparation of Zeolite TON with 3-100 Ratio This example illustrates the possibility of using n-pentylamine as the organic structuring agent and hexahydrate aluminum chloride as the aluminum source.

For this example, n-pentylamine is likewise presalted with hydrofluoric acid.

Make the following reaction mixture: IS i 02 (aerosil), 0.01A
ICI3.6H013CHN, 3HF, 18H20 initial pH-8: introduced morph fraction 20,011
Nucleation with 0,013 g of zeolite TON prepared according to Example 5.

The synthesis medium is then placed in a 20 cm' autoclave made of stainless steel and covered with a jacket made of polytetrafluoroethylene.

It was then dried for 50 minutes in a dryer equipped with a stirrer.
Bring the temperature to 0°C (rotation speed -20t, a+in.

-1).

After the reaction (all-9), the solid obtained is washed and separated from the gel still present by sonication. In this way, the average size of the crystallites is (40X2) micrometers (X 10-6 m) of fiber solids 0.49
Collect g.

The X-ray diffraction diagram of the product is quite similar to that in the specification (Table 1). No significant structural changes were observed after 5 hours of calcination at 800° C. in air.

The chemical composition of the zeolite is then as follows: S i 0 96.7%, A/2030.84%, F-
0.09%, H202.1%.

This is about 200 compared to SiO/A/203. Compatible with do.

that's all

Claims (10)

[Claims] (1) (a) 50-40000 SiO_2/Al_2
Synthetic crystalline zeolite of the TON type, characterized by: O_3 molar atomic ratio, (b) an X-ray diffraction diagram as shown in Table 1 herein, and (c) a fluorine content of 0.005 to 2% by weight. (2) Zeolite according to claim 1, characterized in that it comprises crystals whose size is at least from 0.1 to 250 micrometers (1 to 250 x 10^-^6 m). (3) SiO_2/Al_2O_3 molar ratio is 100 to
Claims 1 and 2 characterized in that it is 40,000.
Zeolite by one of the. (4) (a) consisting of water, at least one source of silica, at least one source of aluminum salt, at least one source of mobilizing agent comprising fluoride ions, at least one source of structuring agent capable of supplying organic cations; forming a reaction mixture with a pH of 9 or less, said mixture having a composition in a molar ratio within the following values: SiO_2/Al_2O_3≧20 F^-/SiO_20.1-6 organic cation/SiO_20.1-6 H_2O/SiO_26-200 (b) maintaining said mixture at a heating temperature of at most 250°C until a crystalline compound is obtained; and (c) calcining said compound at a temperature of not less than 350°C. A method for producing a crystalline synthetic zeolite according to one of claims 1 to 3, characterized in that: (5) A method according to claim 4, wherein the source of structuring agent is a source capable of supplying organic cations selected from monoalkylammonium cations, dialkylammonium cations and monoalkyldiammonium cations. (6) The structuring agent source is a source capable of supplying an organic cation selected from n-butylammonium cation, n-pentylammonium cation, dipentylammonium cation, and 1,4-diammonium, pentane cation. method. (7) Process according to one of claims 4 to 6, in which the mixture is produced using a composition at pH and molar ratio within the following values: pH: 4 to 10, preferably 6 to 9 SiO_2 /Al_2O_3≧100 F^-/SiO_21-3 Organic structuring agent/SiO_21-3 H_2O/SiO_215-80. (8) adding at least one supplementary salt to said mixture at a determined concentration, in a molar ratio of supplementary salt to silica of from 0.1 to 4; and/or one of claims 4 and 5.
8. The method according to claim 4, wherein at least one crystal nucleus of a zeolite produced by silica is added in a weight ratio of crystal/silica from 0.01 to 0.1. (9) Heating temperature of the reaction mixture to 60-210°C, 2
9. A method according to one of claims 4 to 8, maintained for a period of 4 to 1300 hours. (10) Claims 4 to 4, wherein the reaction medium may be dried in a dryer equipped with a stirring device to shorten the reaction time.
Method according to one of 9.